Perry,
Epic event, did the challenger last year and absolutely loved it!
Having a good think about kit is a must, I thought I had it all squared away only to discover once I got to Nairn that it can be quite cold in Scotland in September and that whilst I don't usually wear riding gloves without them my hands were freezing

If you're a mountain biker then the more technical sections shouldn't prove an issue, I did the whole course on a hybrid with lockout suspension and semi-slick tires, a god send on the long road sections and just about good enough on the rough stuff.
Logistics wise it's all sorted for you, turn up the day before in Nairn to drop off bike and register, drop off bag and tent before race and then meet up with said bags at campsite which is next to the bike transition at the end of day one. Wake up stiff the next morning, pack up kit, drop off bag and start day 2, you will then meet up with your bag and bike (depending on end of race transport arrangements made) at the finish

To echo coogie, the 14 mile trek/ run section feels like half of the race, and again with regards to kit it is pretty rocky underfoot for much of the route and as such a sturdy pair of trail shoes would be recommended. I went in some very grippy but somewhat flimsy X-county style shoes, perfect for the first 7 mile run on day one and the steep final descent but by about mile 10 of the trek it felt like someone was hitting the bottom of my feet with hammers.
I suppose what I'm saying is that you really are going to get it all in one race, from Scotland's B roads to technical single track, tarmac footpath to unmarked grassy/ muddy descent down the ridge into Glencoe and everything in between. As long as you prepare yourself adequately then you'll have a great time.
Damn, wish I was doing it this year now